Gripped by drug addiction for over a decade, Mrs Rausing, 48, and her husband Hans Kristian, 49, withdrew from the world and occupied just two squalid rooms in the opulent property in Cadogan Place, according to a friend.

For years they refused to allow anyone else access to the second-floor annexe where they were living.

After Mrs Rausing died in the second-floor bedroom on around May 7, her husband covered her body with a large pile of clothes and bin bags, and sealed off the room with gaffer tape.

When police arrived on July 9 there was a strong smell of decomposition and the bedroom was filled with flies.

The floor plan, based on publicly-available documents held by the Royal Borough of Kensington and Chelsea, shows how the couple were only using a small part of their huge house, which has five storeys plus a basement with a home cinema and a gym.

Passing sentence on Mr Rausing today, Judge Richard McGregor-Johnson told him: “You and your wife had every material advantage and for a time a happy family. Your relapse into the misuse of drugs, together with that of your wife destroyed all that.

“It is graphically illustrated by the difference between the rooms that visitors to your home saw and the utter squalor of the rooms you lived in."